LED Device Light Extraction via 3D Stacking and Transparent Adhesive
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional two-dimensional array light-emitting diode devices face issues with high reabsorption of light due to close proximity of light-emitting diode units, leading to reduced light extraction efficiency and increased risk of connecting failure between units.
Innovation Solution
The arrangement of light-emitting diode units with increased distance between them, specifically with vertical distances greater than 50 μm, and the use of a transparent substrate with a transparent adhesive layer to enhance light extraction efficiency, along with the formation of electrodes and conductive connecting structures to reduce reabsorption and improve electrical connectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If light-emitting diode units are closely arranged in a two-dimensional array, then the device area is reduced and productivity is improved, but light reabsorption increases and light extraction efficiency deteriorates
Solution Approach 1:
The patent transitions from a two-dimensional array arrangement to a three-dimensional stacked arrangement of light-emitting diode units. Multiple layers of LED units are vertically stacked with spacing between layers, allowing light to extract in multiple directions (upward, downward, and sideways) rather than being constrained to a single plane. This dimensional change reduces light reabsorption by distributing emitting units in space while maintaining high device area utilization.
2Device complexity
If light-emitting diode units are closely arranged, then device complexity is reduced, but connecting failure risk increases due to large height differences
Solution Approach 1:
By stacking LED units in multiple layers vertically, the patent creates a three-dimensional structure where connecting structures can route signals along vertical pathways. This reduces the horizontal distance and height differences that connecting structures must bridge, improving connecting reliability while maintaining a relatively simple overall device structure.
Solution Approach 2:
The patent introduces intermediate substrates or support structures between stacked LED layers that serve as connection platforms. These intermediaries provide stable mounting surfaces and electrical connection points, reducing the risk of connecting failures by breaking up long direct connection paths into shorter segments with intermediate support.
3Loss of energy
If transparent adhesive layer is used to bond light-emitting diode units, then light extraction efficiency is improved, but manufacturing complexity increases
Solution Approach 1:
The transparent adhesive layer performs multiple functions simultaneously: it bonds the LED units to substrates, provides electrical insulation between adjacent units, and acts as an optical medium that extracts light from the LED units. By combining these functions into a single material layer, the patent improves light extraction without proportionally increasing manufacturing complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration results in a 5-10% improvement in light-emitting efficiency compared to conventional devices, with a not-near value greater than 50% enhancing the light extraction efficiency and reducing the chance of connecting failures.
Implementation Method 1
the use of a transparent substrate with a transparent adhesive layer to enhance light extraction efficiency
Data Source
AI summary
A light-emitting diode device includes a transparent substrate having an edge side, a peripheral region and a central region surrounded by the peripheral region; and a plurality of light-emitting diode units disposed along the peripheral region and having a first light-emitting diode unit with an edge parallel to the edge side. The central region is devoid of any light-emitting diode unit.